Our nonverbal behavior, and in particular our facial expressions and voice quality, can convey emotional information. Research shows that men and women differ in their nonverbal expression of emotional states. Women are more emotionally expressive, in general, but there are differences with respect to which emotions are expressed. For instance, women express joy and sadness more than men do, but men express anger more than women do. Biological differences inherited from evolution may be at the origin of some of the observed differences, but the differential socialization of girls and boys, different display rules that prevail, and specific gender expectations can also explain those differences. Research suggests the existence of a constant social control on the expression of emotions in that men and women who do not conform to existing display rules must often expect negative social consequences.